251868 has 24 divisors (see below), whose sum is σ = 595840. Its totient is φ = 82800.

The previous prime is 251861. The next prime is 251879. The reversal of 251868 is 868152.

251868 is nontrivially palindromic in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251861) by changing a digit.

251868 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1593 + ... + 1743.

2²⁵¹⁸⁶⁸ is an apocalyptic number.

It is an amenable number.

251868 is an abundant number, since it is smaller than the sum of its proper divisors (343972).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251868 is a wasteful number, since it uses less digits than its factorization.

251868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 297 (or 295 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 251868 is about 501.8645235519. The cubic root of 251868 is about 63.1525654860.

The spelling of 251868 in words is "two hundred fifty-one thousand, eight hundred sixty-eight".